How to make superpower irreplaceable by technology?
If you're aiming for "forever irreplaceable", you can't, unless you tweak very much the rules of your universe - which sorts of means you say "Technology can't replace this superpower because". In a logical and self-consistent universe, this can't be done; you need something mystical that you declare being forever outside of scientific ken (something like natural sea salt being forever different from sodium chloride in some inexplicable way). While non-consistent, lots of people readily believe such things, so it could work for a story. In common parlance we, perhaps incorrectly, refer to this as "magic violates physical laws" (even if, by rights, within a magical universe, physical laws of course include magic).
Otherwise, slightly reworking Clarke's Third Law, we would say that the superpower is indistinguishable from sufficiently advanced technology; but we can still place that "sufficient advancement" point far enough in the future that we needn't care.
The superpower allows doing something that current technology either cannot duplicate, or cannot do so cheaply enough.
This applies to anything, not just "superpowers". For example, the ordinary power of "understanding human speech in a mildly noisy environment with next to no errors", that most people share and think nothing of, is currently "irreplaceable by technology" and will remain so for at least the next five years (or, depending on the noise nature and intensity, maybe even more).
Let us imagine that teleportation is physically possible - some weird quantum manipulation of Heisenberg's indetermination principle at the macro scale, so that five hundred tons of coal mineral might be made to disappear from here and reappear five kilometers distant, at the same height and with no energy expenditure.
This feat is readily replaceable by technology - with monstrous trucks like the Belaz 75-510. Purchase and operational costs would ensure than no one in their right mind would even try to do so, much preferring hiring a professional teleporter.
As for developing the means of performing teleportation technologically, we might need years of experiments on human teleporters, a whole new scientific theory, and so on and so forth, with no return on investment in sight. Might we duplicate this superpower in one thousand years? Maybe. Would we do that anytime relevant? No.
This kind of approach is often lampshaded (e.g. in McCaffrey's Pegasus/Damia series) by the characters possessing the superpower - in McCaffrey's case it's telekinesis, telepathy and teleportation at interstellar distances - wistfully talking of the day when their powers will be available technologically, and they'll be free of becoming just people like any other. Something like that happens in the UnArcana Stars (Ship's Mage) series by Glynn Stewart, with Legatus developing a technological duplicate improving Mars' Rune Array (there, it is hinted that duplicating technologically the teleportation power is instead too difficult, which is the reason behind the... plot behind the series' plot, discovered by one of Mars' AIs).